Monday, March 1, 2010

A team of Harvard chemists led by X. Sunney Xie has developed a new microscopic technique to look at, with colors, a few molecules with fluorescence that can not be detected. Room temperature technique allows the researchers to identify previously unseen molecules in living organisms and accept applications luasdalam Biomedical imaging and research.

Scientists published results on 22 October in environmental issues. Some funding for this project provided by National Science Foundation (NSF).

Fluorescence is a phenomenon where an electron in a molecule absorbs energy from the light and move to the level of higher energy or teralan state. Energy of a consists of light in a unit called photons.

After a few moments on the state teralan, electron back to the previous energy level or ground state by emitting a photon abru. The energy of the photons released released in the wave range of visible light is detected lasted only a few billion seconds.

Most molecules - molecules biologically significant color as hemoglobin - an oxygen-carrying protein in red blood cells - but not mnyerap fluorescent light. In fact, some electrons in the molecules - molecules that release their extra energy but transient with converts them into heat.

"Because these molecules are not fluorescent, they have literally abandoned by the modern optical microscope," Xie explains.

To detect molecules - the molecules are not fluorescent in biological system, Xie and his team developed a new type of microscopy, based on the stimulation emission.

Stimulation emission was first described by Albert Einstein in 1917, and is the basis for today's lasers. In short, this is a process in which the state of the electro teralan, troubled by a photon that has a certain energy, decrease the ground state which produces an additional photon.

Xie microscopic techniques to produce and record the stimulated emission signal with calculations using two rows of input and output vibration heart - heart once. In the input line of vibration, an intensity modulator excitation light of changing living and dying in a five megahertz, or MHz. Modulation creates a stimulated emission signal at the same frequency. Each row has a duration of unexpected vibrations - short thought about 200 femtosecond. One femtosecond is proportional to the seperjuta billionth of a second or 10-15 seconds.

These signal molecules produced by - no fluorescent molecules that provides a highly sensitive image of the molecule - the molecule "that seems" previously.

One of several possible applications of these scientific findings are mapped to the color of the drug delivery - no fluorescent drugs to cells - their target cells. Another possibility is the use of structural imaging - the smallest structures such as vessels - blood vessels, including cells - red blood cells and a single capillary.

Structure and pembuuh - hemoglobin blood vessels that dynamic plays a large role in most of Biomedical process. Two examples are the transition process from the tumor into the inactive state of infectious and delivery of oxygen to the head.

Imaging technologies that form today such as MRI and CT scans of both the lack of spatial resolution required to separate the capillaries - a single capillary or require significant external agents.

Fluorescen labels such as protein, or GFP green fluorescen large - scale is used to observe the activity of biomolecules and to distinguish molecules - molecular targets in a sell. GFP labeling technique provides a very clear image. However, very large proteins that can deliver biological trails good, especially when it is greater than the biomolecules - a fluorescent biomolecules.

The team mapped Xie delivery drug molecules that are not fluorescent and imaging vessels - blood vessels without fluorescen label.

Their latest technique is also capable of imaging the protein - a protein that does not glow in the cells of the five bacteria Escherichia coli.

"While the first study using the experimental pump - the same examiner to provide images of molecules - fluorescent molecules with spatial resolution compared to confocal fluorescence microscopy and high-temporal resolution, this study, for the first time, using stimulated emission microscopy to image molecules - molecules are not fluorescent , "says Zeev Rosenzweig, a program director in NSF Chemical Division.

Although the potential photo-damage, and kekompleksitifitasan and cost of this system is still needed to show these techniques to gain a broader application, "there is no doubt that this study requires a unique way for imaging a wide range of molecules - molecules that are currently not accessible to standard optical microscope now, "said Rosenzweig.

A team of Harvard chemists led by X. Sunney Xie has developed a new microscopic technique to look at, with colors, a few molecules with fluorescence that can not be detected. Room temperature technique allows the researchers to identify previously unseen molecules in living organisms and accept applications luasdalam Biomedical imaging and research.

Scientists published results on 22 October in environmental issues. Some funding for this project provided by National Science Foundation (NSF).

Fluorescence is a phenomenon where an electron in a molecule absorbs energy from the light and move to the level of higher energy or teralan state. Energy of a consists of light in a unit called photons.

After a few moments on the state teralan, electron back to the previous energy level or ground state by emitting a photon abru. The energy of the photons released released in the wave range of visible light is detected lasted only a few billion seconds.

Most molecules - molecules biologically significant color as hemoglobin - an oxygen-carrying protein in red blood cells - but not mnyerap fluorescent light. In fact, some electrons in the molecules - molecules that release their extra energy but transient with converts them into heat.

"Because these molecules are not fluorescent, they have literally abandoned by the modern optical microscope," Xie explains.

To detect molecules - the molecules are not fluorescent in biological system, Xie and his team developed a new type of microscopy, based on the stimulation emission.

Stimulation emission was first described by Albert Einstein in 1917, and is the basis for today's lasers. In short, this is a process in which the state of the electro teralan, troubled by a photon that has a certain energy, decrease the ground state which produces an additional photon.

Xie microscopic techniques to produce and record the stimulated emission signal with calculations using two rows of input and output vibration heart - heart once. In the input line of vibration, an intensity modulator excitation light of changing living and dying in a five megahertz, or MHz. Modulation creates a stimulated emission signal at the same frequency. Each row has a duration of unexpected vibrations - short thought about 200 femtosecond. One femtosecond is proportional to the seperjuta billionth of a second or 10-15 seconds.

These signal molecules produced by - no fluorescent molecules that provides a highly sensitive image of the molecule - the molecule "that seems" previously.

One of several possible applications of these scientific findings are mapped to the color of the drug delivery - no fluorescent drugs to cells - their target cells. Another possibility is the use of structural imaging - the smallest structures such as vessels - blood vessels, including cells - red blood cells and a single capillary.

Structure and pembuuh - hemoglobin blood vessels that dynamic plays a large role in most of Biomedical process. Two examples are the transition process from the tumor into the inactive state of infectious and delivery of oxygen to the head.

Imaging technologies that form today such as MRI and CT scans of both the lack of spatial resolution required to separate the capillaries - a single capillary or require significant external agents.

Fluorescen labels such as protein, or GFP green fluorescen large - scale is used to observe the activity of biomolecules and to distinguish molecules - molecular targets in a sell. GFP labeling technique provides a very clear image. However, very large proteins that can deliver biological trails good, especially when it is greater than the biomolecules - a fluorescent biomolecules.

The team mapped Xie delivery drug molecules that are not fluorescent and imaging vessels - blood vessels without fluorescen label.

Their latest technique is also capable of imaging the protein - a protein that does not glow in the cells of the five bacteria Escherichia coli.

"While the first study using the experimental pump - the same examiner to provide images of molecules - fluorescent molecules with spatial resolution compared to confocal fluorescence microscopy and high-temporal resolution, this study, for the first time, using stimulated emission microscopy to image molecules - molecules are not fluorescent , "says Zeev Rosenzweig, a program director in NSF Chemical Division.

Although the potential photo-damage, and kekompleksitifitasan and cost of this system is still needed to show these techniques to gain a broader application, "there is no doubt that this study requires a unique way for imaging a wide range of molecules - molecules that are currently not accessible to standard optical microscope now, "said Rosenzweig.